Lewis Hamilton will be sorely missed at McLaren, according to technical director Paddy Lowe.
The Briton will bring the curtain down on a long and illustrious career with the team at this weekend's 2012 championship decider in Brazil.
Hamilton has been backed by the team since the age of 11, and since his 2007 graduation into Formula 1 has one world championship crown and 21 race victories - the last of which came just days ago at Austin.
Hamilton has also scored 49 podiums and 25 poles during his time with the team, statistics which Lowe believes underline how keenly his departure to Mercedes will be felt.
"Of course miss Lewis great deal. He is a fantastic driver and a fantastic guy, and we have been through lot of history together," Lowe said in a Vodafone phone-in.
"Personally I have worked with him since 2007 but that's been six years of fantastic racing and great successes – and some tough times as well.
"He is the most fantastic driver. We will all miss him.
"We wish him the best for the future and we will look forward after Brazil to next year.
"Things change in the world, that's how life is but we look forward to a great season next year when Sergio [Perez] arrives and there's great promise there."
Following Hamilton's victory in the inaugural Austin Grand Prix, when he hunted down and passed championship leader Sebastian Vettel, Lowe said he was optimistic the team could carry its form into Brazil and could yet overhaul Ferrari in the race for second in the constructors' championship.
McLaren currently trails the Scuderia by 12 points.
"We're optimistic. There's no reason why we can't carry forward the pace we showed at the weekend in Austin into Brazil," he said.
"There's promise of rain, which will of course add a new element but we'll be pushing very hard to win the race, not just with Lewis as Jenson is equally capable of winning in Brazil and we're going there to get two guys on the podium and hopefully on the top two steps.
"We'll admit that our prime objective is to overhaul Ferrari in constructors.
"We need to get both cars ahead of Ferrari to close gap - that's what we have to do. If there's rain it'll be even more interesting."
In light of Martin Whitmarsh's admission that McLaren had squandered its title chances, Lowe said McLaren's reliability issues have primarily been examples of bad luck and timing.
"We have had a fairly tough time in recent months with reliability – and we haven't been alone with that – but the actual failures have all been things that could happen at any time," Lowe said.
"This car is the most reliable we have had [since 2005] – it's just unfortunate that persistently more problems fall in races opposed to other times. For instance, we did 1500kms in the young driver test without a single issue.
"It has fallen rather unfortunately for us in the races, but the car in general is reliable.
"We just need to keep moving ahead and next season aim for greater reliability. We know that is absolutely a key component."